Phase Diagaram and Thermodynamic Properties |
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| Contrary to the low molecular substance polymers do not show a sharp melting point. Upon heating the material does not suddenly change to the liquid state. Rather the material, within a certain temperature range softens. Cooling brings the material results into a glassy state were the it is very brittle. Especially the linear chain materials can be plastically formed at high temperatures and keep the formed when cooled (thermoplast). If the polymer has formed a network the material is much harder to form and only subject to melting my destroying the network structure. | ||
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| Shown is a generic phase diagram for polymer systems. Sometimes the diagram can also be inverted. While heating the material it may un-mix. Most important for us is the Q -point. At this point a polymer can be considered a random chain. |
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